Are you using metal bushings? A bit of paste wax on them can help with separation.
I tend to use delrin finishing bushings with a CA finish and have had good luck with those. I have finished with just the blank between centers (no bushings) and have had that work out as well.
You are letting the finish buildup too thick. Try putting five to ten coats of thin CA on and then remove the blank and sand tube ends to flush, then put them back on the bushings and apply more CA.
I do leave the bushings on I didn't know that there were delrin I can buy. But I will have to try putting just a few coats on and removing and putting them back on one thing I am using is thick CA from the hobby story.
Ian, thick CA will build up very quickly. The delrin bushing will be your best bet. You can use the paste wax as previously recommended, you may still need to very carefullly part them off to cut the built-up glue at the ends of your tubes.
Same here... I used Derlin CA bushings and often got chipping or tear-out when removing the finished blank. I switched to finishing between centers and problem solved!